In what we assume is an attempt to shift more units among those pesky urban, coastal elites, GM has teamed up with peer-to-peer car-sharing enabler RelayRides. The service allows owners to share their idle vehicles with those in need of a temporary set of wheels. Normally, RelayRides fits a device to cars to set them up with the service. GM’s participation—and the participation of GM owners—comes in a pretty clever way: the company has developed a smartphone app that allows cars to be unlocked by their intended users, leveraging OnStar’s infrastructure to do so.

According to a study by Frost & Sullivan, car sharing, which currently has a user base of about 640,000 as of July of this year, will grow to 4.4 million users by 2016 — which explains why the General wants a piece of the pie. Plus, if people try the cars and like them, they might be more likely to purchase one when the time comes to stop renting rides from other people. The app will allow users to reserve a car, locate it and unlock it, via RelayRides’ database of members. Owners, meanwhile are responsible for setting rates and, we suppose, supplying their own bottles of Febreze. The program launches early next year.